The present invention relates to fluid control valve assemblies.
A fluid control valve assembly is sometimes provided in which a single operating lever operates two control valves which in turn control flow of fluid to fluid operated machines, movement of the operating lever in one direction operating one of the control valves and movement in another direction, usually at right angles to the first direction, controlling movement of the other valve.
With such a fluid valve control assembly, it is sometimes required to rotate the directions in which the operating lever has to be moved to operate the control valves without changing the position of the control valves.
For example, a hydraulic valve control assembly may be used in an excavating vehicle comprising a vehicle body mounted for slewing movement on the vehicle tracks and connected to a boom, the boom being connected to a dipper arm and the dipper arm carrying an excavating bucket. The excavating vehicle is provided with a first hydraulic machine to slew the body, a second hydraulic machine to raise and lower the boom, a third hydraulic machine to pivot the dipper arm relative to the boom and a fourth hydraulic machine to operate the bucket. It is usual in such an excavating vehicle for the hydraulic valves which control the first and second machine to be controlled by a single lever and for the hydraulic valves which control the third and fourth machine to be controlled by a second single lever.
In some countries it is required that movement of these levers in a first mode of operation i.e. in a forward and backward direction, relative to the normal position of the vehicle operator, controls one of the valves associated with each lever and movement in a left and right direction controls the other valve. In other countries it is required that movement in a second mode of operation i.e. in a first diagonal direction relative to the driver controls one of the valves and movement in a second diagonal direction controls the other valve.
As it is undesirable to have to provide vehicles having hydraulic control valve assemblies arranged in one configuration to meet the requirements of some countries and vehicles having hydraulic control valve assemblies arranged in a different configuration to meet the requirements of other countries, it is required to provide a hydraulic control valve assembly in which by means of a simple adjustment the mode of operation can be changed from meeting the requirements prevailing in some countries to meet the requirements prevailing in other countries.